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Highaboosta
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Discussion Starter · #1 ·
I got this from the Corky Bell, "Maximum Boost" book.
This is for gasoline.

The lowest value is .052 hp x cid x absolute pressure (boost + 14.7)
The highest value is .077 hp x cid x absolute pressure

Corky stated that this is from a compliation of years of dyno tests.
 

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Just Me
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Is this only for boosted applications? I took a 350 cu in motor and applied those numbers and with no boost it shows a maximum hp of 396. (.077 X 350 X 14.7) I'm pretty sure I've seen some pretty stout 350s that lay that number to shame.
 

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Is this only for boosted applications? I took a 350 cu in motor and applied those numbers and with no boost it shows a maximum hp of 396. (.077 X 350 X 14.7) I'm pretty sure I've seen some pretty stout 350s that lay that number to shame.
Its for boosted engines on gasoline, so the values at absolute pressure would be for a low compression engine ready for boost.
 

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The difference between the .052 engine and the .077 engine must be better flowing heads. :D lol
 

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Highaboosta
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Discussion Starter · #5 ·
The difference between the .052 engine and the .077 engine must be better flowing heads. :D lol
I'm sure everyone with a turbo program including myself has plugged their numbers in there. I was happy with what I got for a hack assembly.

I saw some HP numbers thrown out on the airflow bitching thread that were beyond the .077 factor so I chalked them down to bullshit.
 

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Highaboosta
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Discussion Starter · #8 · (Edited)
Here's the NRE engine on youtube,
http://www.youtube.com/watch?v=atZq47WWqc4&feature=player_embedded

Here's the formula calculated backwards from the know hp,

632ci. x 41.7 map x X = 1930 hp
X = .073

Even with real big turbo's and as good components as money will buy they still didn't get quite to the .077 high end number. Mighty close though.
 

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Highaboosta
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Discussion Starter · #10 · (Edited)
Now I have a formula to calculate out what I knew was bullshit when I read it a few months ago.

BS#1) 604 ci x 28.7 map x X = 2022 hp
X = .116 (this one was supposedly on pump gas too)
BS#2) 620 ci x 46.7 map x X = 3500 hp
X = .120
 

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Highaboosta
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Discussion Starter · #12 · (Edited)
Is that a gasoline engine Bob ?
That's what the whole formula is based on.
No gas engine is ever going to be able to run at the boost levels to make the HP that Methanol or Ethanol can.

I suppose you could make an educated guess by deducting a % for methanol and not using a boost number above what gas could run on to get a comparison.

What were the KNOWN specifics on that motor ?
 

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Is that a gasoline engine Bob ?
That's what the whole formula is based on.
No gas engine is ever going to be able to run at the boost levels to make the HP that Methanol or Ethanol can.

I suppose you could make an educated guess by deducting a % for methanol and not using a boost number above what gas could run on to get a comparison.

What were the KNOWN specifics on that motor ?
It was on meth. The biggest reason it makes the power it does is an incredably effiecent combustion chamber, drop dead perfect ports, with perfect inclined valve angles, 4 valve twin over head cam. And the fact that it is only 181 cid. On gas it would probably still top .009.
Every 4 valve over head cam japanese import owes it heritage to this motor. The original design goes all the way back to the 30s
It won Indy 27 times, and took all three positions on the podium for an entire decade. More than one Indy race was run with this being the ONLY engine in the field. From 1950 thru 1960, it won the pole 10 times out of those 11 years. I would have won another 12-15 races if they hadn't lower the boost limit to a max 26 psi from the 45 psi these things were designed to run at. And that was only done because Ford cried so damn much, and swung a bigger hammer than some little ass enigine shop in Los Angeles. They have NO HEAD GASKET NO HEAD BOLTS, to blow. The cylinders and head are one unit. The lower end was almost as bullit proof. There were no main caps, and the lower end didn't split like a VW or motorcycle case. The crank was lowered into the one piece crankcase while it stood vertical, and had cross shaped main webs that bolted to the crankcase with 2 bolts on each cross, for a total; of eight bolts per main. They thrived on boost. It was the ultimate turbo motor. getting 1200 out one today would be a piece of cake.



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Highaboosta
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Discussion Starter · #14 · (Edited)
I agree that engine as well as other specialized race engines like F1's are going to be beyond that formula. I threw in some estimated offset factors for gas and 2 bar boost and got .105 for that indy car engine.

To quote the book Corky Bell said, "Of known dyno runs on piston engines with a variety of turbo systems, the lowest output we have achieved is .052 bhp/cid psi and the highest is .077 bhp/cid psi. The variance is due to the engines basic designs"

For any of the engines we would use on this website the formula is going to apply. At least for the handful of us who run turbo's.

I deducted 5% from the HP number for using alcohol fuel and came up with a .073 for my pile.
 

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Most Indy deals run RPM's to the moon. Which is a big plus for HP numbers.
 

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I agree that engine as well as other specialized race engines like F1's are going to be beyond that formula. I threw in some estimated offset factors for gas and 2 bar boost and got .105 for that indy car engine.

To quote the book Corky Bell said, "Of known dyno runs on piston engines with a variety of turbo systems, the lowest output we have achieved is .052 bhp/cid psi and the highest is .077 bhp/cid psi. The variance is due to the engines basic designs"
For any of the engines we would use on this website the formula is going to apply. At least for the handful of us who run turbo's.

I deducted 5% from the HP number for using alcohol fuel and came up with a .073 for my pile.
Exactly. And the bottomline in any engine that performs better than another, inch for inch, in roughly the same RPM range, is almost totally due to flow. No Olds or Buick is going to unseat the BBC. And for no reason other than flow. Whether its due to small bores, or just plain inefficient heads. Its what seperates hemis from wedges, flatheads from OHVs, pushrod from OHC, 2Vs from 4Vs.

Trying to compete with a 2v pushrod against a 4V twin OHC motor is like pissing in the wind. And yet, below the heads, they are all pretty much the same.

FLOW RULES!



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It was on meth. The biggest reason it makes the power it does is an incredably effiecent combustion chamber, drop dead perfect ports, with perfect inclined valve angles, 4 valve twin over head cam. And the fact that it is only 181 cid. On gas it would probably still top .009.
Every 4 valve over head cam japanese import owes it heritage to this motor. The original design goes all the way back to the 30s
It won Indy 27 times, and took all three positions on the podium for an entire decade. More than one Indy race was run with this being the ONLY engine in the field. From 1950 thru 1960, it won the pole 10 times out of those 11 years. I would have won another 12-15 races if they hadn't lower the boost limit to a max 26 psi from the 45 psi these things were designed to run at. And that was only done because Ford cried so damn much, and swung a bigger hammer than some little ass enigine shop in Los Angeles. They have NO HEAD GASKET NO HEAD BOLTS, to blow. The cylinders and head are one unit. The lower end was almost as bullit proof. There were no main caps, and the lower end didn't split like a VW or motorcycle case. The crank was lowered into the one piece crankcase while it stood vertical, and had cross shaped main webs that bolted to the crankcase with 2 bolts on each cross, for a total; of eight bolts per main. They thrived on boost. It was the ultimate turbo motor. getting 1200 out one today would be a piece of cake.
And this mystery engine is... what? Offenhauser?
My dad is working on an Aston Martin 2.6 l inline six, works in a similar way where crank assembly, with pre-assembled circular bearing supports, is dropped vertically into the crankcase. No main caps in the common sense. It has conventional bolt-on heads and piston sleeves though. DOHC and 2 plugs per cylinder, sidedraft webers. Seemes fairly advanced for 1952. He has the actual crankshaft from the Aston Martin DB-2 convertible that the chick drove in Alfred Hitchcock's "The Birds" movie.
 

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Yeah, its an Offy. And as advanced as your dads Aston looks for being a 50s engine, imagine that the offy's basic design goes back to the early 20's by Harry Miller. Although updeated through the years, the last ones in the 70's/80's are very very close to the Offy's built in the 30s after Fred Offenhauser bought the company in Millers bankruptcy.
There were a number of engines that used a closed crankcase, including very early Caddies. But it was the one piece cylinder/head deal that made the offys bullet proof to boost.

Your dads car sounds cool. Those euro guys were way ahead of us in the perfomance department. But they suffered realiabilty with the littest things. English stuff was notoriously bad for bad electrics. But damn did they know how to engineer a motor. T

The 20's Miller(later the Offy) design was really nothing more than a improved 1913 Peugeot. So while we were stuck with OEM flatheads, the euros were running around with DOHCs



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Now I have a formula to calculate out what I knew was bullshit when I read it a few months ago.

BS#1) 604 ci x 28.7 map x X = 2022 hp
X = .116 (this one was supposedly on pump gas too)
BS#2) 620 ci x 46.7 map x X = 3500 hp
X = .120
You have to remember when he did all of this testing and came up with his calc, the turbos were nothing like we have today and the EFI systems didn't exist. It is pretty easy to double the horsepower the engine makes at 14.7psi of boost and another 30%+ at another 14.7psi.

I personally saw an engine dyno test Big Block 540ci that made 1980hp at 16psi on race fuel with twin 88s. Another Alcohol small block Ford that made 2200hp at 30psi on methonal.

BS#1 if the engine is anything should make that easy, pump gas well maybe not... It takes alot of work to run some high boost numbers on pump.

BS#2 46psi and a 620ci If it didn't make that I would be real disappointed.
 

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Highaboosta
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Discussion Starter · #20 · (Edited)
You have to remember when he did all of this testing and came up with his calc, the turbos were nothing like we have today and the EFI systems didn't exist. It is pretty easy to double the horsepower the engine makes at 14.7psi of boost and another 30%+ at another 14.7psi.

I personally saw an engine dyno test Big Block 540ci that made 1980hp at 16psi on race fuel with twin 88s. Another Alcohol small block Ford that made 2200hp at 30psi on methonal.

BS#1 if the engine is anything should make that easy, pump gas well maybe not... It takes alot of work to run some high boost numbers on pump.

BS#2 46psi and a 620ci If it didn't make that I would be real disappointed.
Read that again Brian, It was MAP not psi.

That book is from 1998.

I agree with your 2nd sentence.
I don't believe the 540 ci/1980 hp with 16 psi on any gas. That's a world beyond your 2nd sentence.
 
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